• Journal of Preventive Medicine and Public Health
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• v.56 no.4
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• pp.303-311
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• 2023

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, 'medflex' and 'mediation', to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

• International Commerce and Information Review
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• v.11 no.3
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• pp.391-408
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• 2009

This study first designates the factors affecting Foreign Direct Investment (FDI) in order to analyze the FDI in Korea, and calculates the Korean FDI index by using various designated variables and by applying Factor Analysis Technique. In addition, it attempts to understand the influence wielded by the foreign investment variables of foreign multinationals on FDI in Korea, by setting to analyze & verify Environmental Factors and the overall model based on FDI in Korea. Through an emprical analysis of USA, Japan, EU, China, as our hypothesis, we could verify that the positive effects(+) among the decisive factors of FDI in Korea include the market size, the mean earning rate of domestic manufacturing industries, and the marketing capacities of foreign corporations, while the negative effects(-) include the ratio of taxation on domestic manufacturing industries. Other FDI factors have various effects on each, so some factors show the same effects as the hypothesis while others show separate effects. In addition, the only nation for which the effects of FDI factors in Korea coincide with the hypothesis completely is the USA, while other nations (such as Japan, EU, China) have some effects that conform to the hypothesis, but other effects do not accord with it.

• Journal of Korean Public Health Nursing
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• v.13 no.2
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• pp.12-25
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• 1999

This study examines individual determinants of hospital days in community-dwelling elders by estimating a linear structural equation model based upon Andersen's behavioral model. Data were collected through a national survey of elders in Korea in 1994. The subjects for this secondary data analysis were 1687 non-institutionalized elders aged 60 years or older. Except for the effect of age and gender on family help. the predisposing components had direct effects on the enabling components. Of the effects of the enabling components. family help had a direct effect on self-evaluated health; economic status had a direct effect on chronic disease and self-evaluated health; and access had a direct effect on chronic disease. functional health status and self-evaluated health. Of the enabling components. residence and family help directly affected hospital days. Self-evaluated health revealed the greatest direct effect on hospital days followed by functional health. Overall. the effects of the predisposing components and the enabling components on hospital days were not prominent. Since the model explained only $4\%$ of the variance in hospital days. the magnitude of the effect of the need components cannot be judged in terms of equity of distribution of health services. In particular. the effect of family help in the model reveals the importance of family support in health management of elders. The implications of these analyses for improving the proposed model of hospital days were discussed.

• Korean Journal of Child Studies
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• v.29 no.1
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• pp.87-101
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• 2008

This study examined the influence of family risk factors, ego-resilience, and quality of peer relationships on adolescent problem behaviors in a sample of 335 8th grade students (178 boys and 157 girls). They responded to four kinds of questionnaires. Data were analyzed by independent t-tests, correlations, and multiple regressions. Results showed that family risk factors had direct effects on ego-resilience which directly affected quality of peer relationships. Family risk factors, ego-resilience and quality of peer relationships had direct effects on internalizing problem behaviors. Family risk factors and quality of peer relationships had direct effects on externalizing problem behaviors. Family risk factors indirectly influenced adolescent internalizing/externalizing problem behaviors through ego-resilience and quality of peer relationships.

• Korean Journal of Childcare and Education
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• v.16 no.5
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• pp.47-67
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• 2020

Objective: The main purpose of this study was to investigate the direct effect of maternal parenting behavior and indirect effects through preschoolers'executive function on three types of social behavior, prosocial, aggressive and withdrawn behavior. Methods: A total of 299 mothers and their preschool-aged children were the subjects of this study. Mothers completed the questionnaire that included measures of their parenting behavior, preschoolers' executive function, and social behavior. Results: First, mothers' positive parenting behavior had a direct effect on preschoolers' prosocial behavior, and mothers' negative parenting behavior had direct effects on preschoolers' aggressive and withdrawn behavior. Second, mothers' positive parenting behavior had indirect effects on preschoolers' prosocial, aggressive and withdrawn behavior through preschoolers' executive function. In contrast, indirect paths from maternal negative parenting behavior to social behavior through preschoolers' execution function were not significant. Conclusion/Implications: These findings underscore the importance of executive function during early childhood and suggest the need for effective parenting programs to promote executive function.

• Journal of Korean Academy of Nursing
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• v.34 no.3
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• pp.541-551
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• 2004

Purpose: This study was to identify the effects of the predictive factors of Internet addiction and to develop a predictive model that explains Internet addiction among adolescents in Korea. Method: Data was collected from 664 adolescents in Puasan and Ulsan. Data analysis was done using the SPSS 10.0 Win Program for descriptive and correlational statistics and the LISREL 8.53 Win Program for Covariance structural analysis. Result: The fit of the hypothetical model to the data was moderate, it was modified by deleting four paths. Compared to the hypothetical model, the revised one had a better fit to the data($\chi^2$/df=6.50, GFI=.99, AGFI=.90, RMR=.02, NNFI=.88, NFI=.98, CN=279). Gender, friend support, and loneliness had significant direct effects on Internet addiction. The direct and indirect effect of self-esteem on Internet addiction was significant. The indirect effect of family support on Internet addiction was significant but its direct effect was insignificant. The direct and indirect effects of stress and impulsiveness on Internet addiction were significant but their total effects were insignificant. Conclusion: Finally, to decrease loneliness, and to increase family support and self-esteem, an effective intervention program and education should be developed to prevent Internet addiction of adolescents.

• Korean Journal of Childcare and Education
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• v.14 no.1
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• pp.1-20
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• 2018

Objective: The purpose of this study was to examine the direct and indirect effects (through working mothers' overprotective parenting behavior) of working mothers' separation anxiety and job satisfaction on preschoolers' separation anxiety. Methods: A total of 251 working mothers with preschool-aged children participated in this study. Mothers completed a questionnaire concerning their separation anxiety, job satisfaction, overprotective parenting behavior, and preschoolers' separation anxiety. Data were analyzed using t-test, one-way ANOVAs, partial correlations and path analysis. Results: In terms of direct effects, working mothers' separation anxiety had a direct effect on preschoolers' separation anxiety. However, job satisfaction did not have a direct effect on preschoolers' separation anxiety. With respect to indirect effects, working mothers' separation anxiety indirectly influenced preschoolers' separation anxiety through their overprotective parenting behavior. However, mothers' job satisfaction did not have an indirect effect on preschoolers' separation anxiety. Conclusion/Implications: Findings from this study emphasize the importance of reducing mothers' separation anxiety in order to prevent preschoolers' separation anxiety.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3245-3271
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• 2016

To obtain well-dehazed images at the receiver while sustaining low bit rates in the transmission pipeline, this paper investigates the effects of image dehazing methods using dehazing contrast-enhancement filters on image compression for surveillance systems. At first, this paper proposes a novel image dehazing method by using a new method of calculating the transmission function—namely, the direct denoising method. Next, we deduce the dehazing effects of the direct denoising method and image dehazing method based on dark channel prior (DCP) on image compression in terms of ringing artifacts and blocking artifacts. It can be concluded that the direct denoising method performs better than the DCP method for decompressed (reconstructed) images. We also improve the direct denoising method to obtain more desirable dehazed images with higher contrast, using the saliency map as the guidance image to modify the transmission function. Finally, we adjust the parameters of dehazing contrast-enhancement filters to obtain a corresponding composite peak signal-to-noise ratio (CPSNR) and blind image quality assessment (BIQA) of the decompressed images. Experimental results show that different filters have different effects on image compression. Moreover, our proposed dehazing method can strike a balance between image dehazing and image compression.

• Journal of Korean Academy of Nursing Administration
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• v.17 no.3
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• pp.284-292
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• 2011

Purpose: The purpose of this study was to examine the causal relationships among quality of hospital SCM (system quality, information quality, service quality), perceived usefulness, user satisfaction and logistics performance by hospital staff. Methods: A survey using a structured questionnaire was conducted with 276 hospital staff. Analysis of the data was with both SPSS Win 18.0 for descriptive statistics and AMOS 8.0 for the structural equation model. Results: The hypothetical model yielded Chi-square=8.121 (p=.087), df=4, $x^2$/df=2.030. GFI=.989, AGFI=.942, RMSEA=.066, NFI=.995, CFI=.997 TLI=.990 and showed good fit indices. Three dimensions of quality of SCM had significant direct effects on perceived usefulness. System and service of quality of SCM had significant direct effects on user satisfaction. Perceived usefulness had significant direct effects on user satisfaction. User satisfaction had significant direct effects on logistics performance. Conclusion: These results suggest that logistics performance can be enhanced by user satisfaction, user satisfaction can be enhanced by perceived usefulness, and perceived usefulness can be enhanced by quality of hospital SCM. Further study with various hospitals and various variables is necessary.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.285-287
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• 1998

본 논문에서는 다양한 멀티미디어 스트림(multimedia stream)을 재생할 수 있는DirectShow SDK를 이용하여, 비디오의 특수효과를 구현하기 위한 변환 필터(Transform filter) 제작 방법에 대해 소개한다. DirectShow는 여러 가지 포맷(MPEG, AVI, MOV, WAV)으로 부호화된 digital movie나 sound를 재생할 수 있는 run-time(.ock)과 dynamic-link library (DLLs)를 제공하여 필터의 제작을 용이하게 한다. 본 논문에서는 디지털 영상 특수효과 중에서 Clip이라는 특수효과를 예로하여 변환 필터를 제작하는 방법을 소개한다. 또한 DirectShow Documentation에서 제공된 변환방법을 수정하여 변환필터의 입력 pin에서 출력 pin으로의 불필요한 복사를 줄임으로써 수행 속도를 개선하는 특수효과 구현 방법을 제시한다.